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Mechanics of Materials (Libre)
United States
Registrace 30. 10. 2015
Mechanics of Materials lectures recorded in class of Dr. Nicoals Ali Libre at Missouri University of Science and Technology.
scavenger hunt code for CE2210 students: 23N6E0
scavenger hunt code for CE2210 students: 23N6E0
Video
Mechanics of Materials in Practice (Guest Speaker Jon Kuchem)
zhlédnutí 796Před 2 lety
Practical applications of Mechanics of Materials in the real world are discussed in this talk. Jon Kuchem, a structural engineer at Burns & McDonnell, and a former student and Teaching Assistant of Mechanics of Materials share his experiences and visions to inspire current students and the next generation of engineers.
M21- Indeterminate beams with flexible supports and gap
zhlédnutí 2,8KPřed 2 lety
The compatibility of deformations in the indeterminate beams with flexible supports was discussed in this lecture. In addition, and example of indeterminate beam in which there is a gap between beam and support is presented. 0:00 Introduction to indeterminate beams and simple example 5:04 Example of indeterminate beam with flexible support 10:13 Example of indeterminate beam with gap at the sup...
Example of indeterminate axial element with spring
zhlédnutí 3KPřed 2 lety
An example of indeterminate structure with axial members and spring
A detailed example of an indeterminate structure with axial members
zhlédnutí 1,2KPřed 2 lety
A detailed example of an indeterminate structure that consists of a rigid element connected to a few axial elements. This example explains how the compatibility of deformation and similar triangles could be used for analyzing indeterminate axial members. 0:00 Problem statement 0:20 Step 1: Equilibrium equations 3:56 Step 2: Force-displacement relation 4:42 Step 3: Compatibility of deformations ...
Indeterminate axial members (Theory and examples)
zhlédnutí 4,3KPřed 2 lety
What is an indeterminate structure and how it could be analyzed? This lecture discusses this concepts and explains how the compatibility of deformation could be used for analyzing (determining internal forces) of a system of axially loaded eleements. The main learning outcomes are: - Distinguish between determinate and indeterminate structures - Identify the degree of indeterminacy in structure...
The Concept of Engineering Design (Method of allowable stress)
zhlédnutí 4,1KPřed 2 lety
Here we discuss about the basic concepts of engineering design. We will learn about the uncertainty and risk associated with engineering design and how safety margin should be set to avoid failure. The allowable stress method described here, uses the safety factor to achieve the required safety margin. The main learning outcomes are: - Distinguish between maximum stress and allowable stress - I...
M33- Combined loading (Right hand rule in 3D structures)
zhlédnutí 6KPřed 3 lety
Learning outcomes: Apply the right hand rule in 3D structures Calculate normal and shear stresses caused by combined loading Determine the sign of normal and shear stress on the section
M21- Indeterminate beams (Algorithm and examples)
zhlédnutí 2,8KPřed 3 lety
What are indeterminate beams and how these structures could be analyzed? In this video we discuss these questions, present algorithm for solving problems and practice some examples.
M20- Conceptual questions in beam deflections
zhlédnutí 2,3KPřed 3 lety
Reviewing some conceptual questions in beam deflection in order to understand the boundary conditions in the integration method as well as the relation between loading, shear, moment, slope and deflection of beams.
M20- Deflection in beams, part 2 indirect deflection caused by slope
zhlédnutí 3KPřed 3 lety
In this video we discuss how to calculate deflection of beams using superposition method. In particular we focus on the calculation of indirect deflection caused by slope of the beam.
CE5207 Approximation using shape functions on subdomains part 2
zhlédnutí 142Před 3 lety
CE5207 Approximation using shape functions on subdomains part 2
CE5207 Approximation using shape functions on subdomains (part 1)
zhlédnutí 405Před 3 lety
CE5207 Approximation using shape functions on subdomains (part 1)
Deformation of axial members with variable cross section area (Lecture and examples)
zhlédnutí 9KPřed 3 lety
The theory of deformation in axial members with variable loading and variable cross section area is presented and discussed.
Designing a cable connection in an arch cable stayed bridge
zhlédnutí 1,5KPřed 3 lety
Designing a cable connection in an arch cable stayed bridge
Example of stress analysis in axial element
zhlédnutí 1,7KPřed 3 lety
Example of stress analysis in axial element
Pressure vessels (part2 Shear stress and deformations)
zhlédnutí 12KPřed 3 lety
Pressure vessels (part2 Shear stress and deformations)
Pressure vessels (part1, Stress analysis)
zhlédnutí 18KPřed 3 lety
Pressure vessels (part1, Stress analysis)
M28- Mohr's circle (part2 3D Mohr's circle, maximum absolute and maximum in-plane shear stress)
zhlédnutí 38KPřed 3 lety
M28- Mohr's circle (part2 3D Mohr's circle, maximum absolute and maximum in-plane shear stress)
M28- Mohr's circle (part1- Basic concepts)
zhlédnutí 7KPřed 3 lety
M28- Mohr's circle (part1- Basic concepts)
Stress transformation (part1 basic concepts)
zhlédnutí 14KPřed 3 lety
Stress transformation (part1 basic concepts)
Normal stress and shear stress on a welded seams using stress transformation equations
zhlédnutí 3,6KPřed 3 lety
Normal stress and shear stress on a welded seams using stress transformation equations
Example of bending in a built-up member
zhlédnutí 2,8KPřed 3 lety
Example of bending in a built-up member
Maximum allowable torque of a compound tube
zhlédnutí 3,1KPřed 3 lety
Maximum allowable torque of a compound tube
Example of deformation of spring due to axial force
zhlédnutí 779Před 3 lety
Example of deformation of spring due to axial force
I've been pondering about the right hand rule for a while now. just a 3mins watch, I got it alright. Thanks for saving me.
Very helpful 🎉🎉
Very helpful 🎉🎉
Finally solved the one of my biggest problem ❤
Please check if the area of the bolt in Example 3(case 2) is correct. To me it is 0.1963 in^2 not 0.0977 in^2.
Final answer ?
❤
thank you for thisssss! big help, Sir!
Have a mistake in the diameter = 12mm not 8mm at minute 8:02
Wonderfully explained!!
Well explained great work👍
thank you
Sir please it seems shear stress values(positive or negative) depends on the angle u choose.
Thanks for your sharing!
Outstanding 😍
Direct shear is t=V/A (as you call it average shear), transverse shear is t=VQ/It... why in a beam bending problem is there no direct shear (no t=V/A)? For instance, when we have a key in a keyway on a shaft, the key undergoes direct shear and no bending (this makes sense to me as there is no distance between the applied external loads)... but why is there no direct shear when the external loads are far apart (such as a cantilever beam with a point load at the end)?
what if the rod was below the wood beam instead of above it, would the compatability equation still be the same?
Yes, same!
@@consaidercordo3770 thanks
is the answer 0.003685 mm ?
BY FAR THE BEST EXPLAINTAION I FOUND. Thank you!
To be honest, this is the best explanation I have seen so far. The animation truly helps us see what goes on in these situations, it's very informative. Many thanks for your efforts!
Bro cooked so hard
Where did the 288mm^2 came from in 5:30?
This is great quality. Thank you, sir!
I appreciate the effort but there are some errors in the calculations...
Sir you are great 💛😊👍 ... You are my helper 😊🌼😊...
Thank you! If you could raise the video image clarity would be great!
Thank you.
I never really understood the difference between normal and bearing stress. can anyone explain?
You're not alone LOL
So hoop can also be 2 * longitudnal stress
Yes In cylindrical PV, the hoop stress is twice of the longitudinal stress
21:04. Why does delta1 = delta2? for category 2. Thank you
Why shear stress area we need to use bolt surface area?
Hello sir, could you please explain when and why we need to consider stress transformation in design, like in bended members, compressed members, etc due to the significance effect of it. It's quite confusing to me that the tranverse shear and the shear that caused by the stress transformation which one is bigger or needed to be considered in some specific cases. Thank you in advance
How would you complete the analysis if a further steel tube sized D= 3 and d=3.5 with L= 1ft was inside ? Do you add the elastic moment of the two materials together or analyse each member separately?
That would be an indeterminate beam and the load distribution between the two, depends on the rigidity (EI) for each element. You may check this video for details: czcams.com/video/3kTMMNouHHo/video.html
@@MechanicsofMaterialsLibre Thank you. I have tried to complete my analysis but there is still some confusion. The analysis I am performing is as follows: Two circular hollow sections inside at different sizes that fixed to the ground and are overhang at the other end as shown in the video above. The question is: A 1.1m in height circular hollow section (CHS) is sized 42.40mm (diameter ) x 2.0mm (thickness ) with a 0.3m in height (CHS) inside that is sized 38.10mm (diameter) x 2.0mm (thickness ). There is a point load of 0.74kN acting on the top of the 1.1m tube, and it is assumed that both CHS are fixed at the bottom. How is the bending moment and deflection for the two posts calculated separately? I am finding it difficult to draw the deflection diagram since the smaller section would act to resist? How is the load distributed? by solving the slope equations?
the only one video of them all that explained me that stress transformation
This was an excellent explanation thank you!
Why the stress is not negative when compression is there?
Yes sigma_y is negative but here we used the absolute value since it is not changing the final answer.
I have watched hundreds of videos on the subject of 3D stress analysis, and this is the best one I have found. You are brilliant! Thanks.
Such a great explanation!! THANKS!
amazing explanation thanks for your time sir
sir how can we get those pdfs?
perfect explanation, thank you so much
❤
Thank you so much! I finally understand the angles
Its very helpful. Thanks you so much !!!
Nicely explained Sir. You really nailed it. Fantastic.
Very GOOD!
10:53
Amazing 🤩
Concept is clear Thank you 👍 Please upload more videos.
I understand your logic that A=πdt BUT that does not give an entirely accurate answer. Subtracting the area of the circle formed by the inner perimeter from the area of the circle of the outer perimeter, i.e. A=π(dt-t^2), derived from A=π*rsubouter^2 - π*rsubinner^2, will give a 100& accurate answer but different than the equation you are using. Why would you use an equation that does not give you an accurate answer when there is a better equation that you can use?
The approximate area A_approx=πdt in thin walled pressure vessels (where d/t > 10) is close enough to the exact area A_exact = π/4*(d_outer^2-d_inner^2) and significantly simplifies the resultant stress equation. Note that 5% limit is usually considered sufficient in many engineering applications and such limit is satisfied in many thin walled pressure vessels. Thick walled pressure vessels have a non-uniform stress distribution and the calculation is totally different. Hope that helps.
@@MechanicsofMaterialsLibre Thank you for your explanation professor although I must strongly disagree with your approach. Where does it say exactly that there is an across the board 5% error limit that is acceptable in many engineering applications? Surely that would depend on a case by case basis and I doubt it would apply to error in your mathematical calculations. Is it then okay to say that 10 + 10 = 19 if, let us say, I am designing a nuclear reactor? How do you fit a 20 mm nut into a 19 mm bolt, it is only a 5% error? I get it, sometimes engineers have to accept a certain margin of error but surely not when you can help it?! Error margins are there for things like imperfections in materials, irregularities during manufacture and assembly, non-uniform stress distribution, factors that are impossible to accurately quantify. I do NOT believe error margins are there to excuse sloppy mathematical calculations purely for the sake of simplicity, especially not in an engineering dicipline. Frankly I would call that laziness and irresponsible. What happens when that unnecessary error is amplified when repeated in further calculations? What do you tell the Board of Enquiry when the structure collapses? "I made a few 5% errors because that was simplest but it was all within error margin."? As for simplifying the stress equation, yes I agree, multiplying 3 variables is MARGINALLY simpler than doing a simple area calculation for a circle, but the latter is not exactly rocket science either. This is basic elementary school mathematics we are talking about, you mean to tell me that doing an area calculation for a circle is too complex and that it is better to do an inaccurate calculation instead, purely for the sake of simplicity? I do not mean any disrespect but, either I do not understand the merit of your approach OR I simply cannot accept such a flagrant drop in standards. I think I will just keep doing the calculation the correct way for now. I recognise that you are an eminent professor in engineering and I am just a student so perhaps it is arrogant of me to say, but surely you can't be right?
This is a whole study in itself of tolerances. Anyhow you should know that while performing any calculations we are approximating. even in FEA, most fields have strict guidelines and rules like for steel structures in europe it EC3 and for piping its EN13480. Both are very conservative and in most cases will have a safety factor of 1.2 or more. I think you shouldn't be hard focused on how you got the #, every engineering problem you will work on will have some governing rules to define your #. Point of the tutorials is to get yourself familiar with procedures and approach to solutions.@@GryffieTube
ASME B&PV code uses precisely this approximation. THE PRESSURE FORCE EQUALS (w/4)D^2P WHILE THE RESISTING FORCE EQUALS (r)DTS. WHEN THE TWO ARE EQUATED, (v/4)D^2P = (w)DTS AND SOLVING FOR T = PD/AS = PR/2S. From European standard AD 2000 section B1 5 on the design of thin walled pressure vessels: The required wall thickness s is, in the case of spherical shells s = (D_a * p)/(40K/S * v + p) + c_1 + c_2 s wall thickness D_a out side diameter p design pressure K design strength S safety factor v Poisson's ratio Here expansion is approximated, but the same approximation is made. ASME B31.3 uses the same approximation when calculating stress in curved piping. This is not "@MechanicsofMaterialsLibre 's approach". This is an international design standard (based on barlow's formula) that has been used for decades in everything from rockets to nuclear power plants.
Barlow's formula is intrinsically an approximation(in far more ways than you have mentioned), and there are certainly more accurate ways of calculating stress in a pressure vessel. This video is about Barlow's method, if you wan't a more advanced technique, they really are not hard to find.